The present invention relates to a closing appliance used in a flexible tube which connects blood bags without damaging sterility in the system.
When blood is collected from a donor, cellular components of blood are usually separated from plasma prior to storage or use thereof. In general, separation of blood is carried out by centrifugal separation method whereby blood is separated into an upper plasma layer, a middle thin soft-film-like layer probably containing platelets and white cells, and a lower layer comprising red cells.
Bags made of synthetic resin are used in separating blood into cellular components and plasma. FIG. 4 is a plan view of an example of a double-type blood bag, and FIG. 5 is a sectional view explaining a conventional closing appliance in a flexible tube. Blood is collected into a blood bag 11 through a blood-collecting-tube 15. After collection is performed, the blood-collecting-tube 15 is sealed near the blood bag 11 and a part of the blood-collecting-tube 15 including a blood-collecting-needle (not shown) is separated from the residual portion. Then, both the blood bag 11, and a child bag 12 connected to the blood bag 11 through a connector 13 and a connecting tube 14 are processed by centrifugal separation method.
After centrifugal separation, plasma separated from blood is moved into the child bag 12 through a communicating tube 2 of the closing appliance and the connecting tube 14, by holding the connector 13 with hands and breaking a thin-walled portion 4 of the closing appliance.
On carrying out centrifugal separation in the above-mentioned process, however, there is a problem of the flexible tube that a tip 7 of the closing appliance frequently break through.
It is an object of the present invention to provide a closing appliance having an improved tip which does not break through a flexible tube.